First of all, go to advanced boot options, and see whether last known good configuration works or not
can you boot into safe mode? If so, try to do system restore, if that doesn't work as well, try to do a clean boot, followed by an advanced clean boot and a hardware clean boot.. these steps might help ..
hardware clean boot :
Follow the steps below to perform hardware clean boot
1. Right click on My Computer -> Properties
2. Hardware Tab -> Device Manager
3. Right Click on Sound Card, Video Adapter, Network Adapter one by one and click disable
4. Reboot the computer. If the problem is fixed then you can enable the hardware devices one by one to find the exact device that cause the problem